Feudal Japan, at the dawn of the 18th century: fleeing monstrous demons, a young half-Japanese, half-British orphan named Kai finds refuge with the benevolent lord of Ako Castle. Years later Kai (Keanu Reeves) is a loyal servant beloved by his master's beautiful daughter Mika (Kou Shibasaki) but distrusted by the samurai including their valorous leader, Oishi (Hiroyuki Sanada). Working in tandem with ambitious rival Lord Kira (Tadanobu Asano), evil shapeshifting witch Mizuki (Rinko Kikuchi) engineers Lord Asano's (Min Tanaka) disgrace in the eyes of Shogun Tsunayoshi (Cary-Hiroyuki Tagawa). As a penance, Asano commits ritual suicide leaving his forty-seven warriors “ronin” or masterless samurai and casting Kai into the wilderness bereft of his true love. Following a year spent in unjust imprisonment, Oishi seeks out Kai's help to reunite the forty-seven ronin in an audacious revenge attack.

As the opening narration informs viewers “to know the story of the forty-seven ronin is to know the story of old Japan.” Known in Japan as Chushingura the story of the forty-seven ronin is nothing less than their national legend, exemplifying the ideals of the samurai code of honour or “bushido” along with concepts of Nipponese heritage and cultural identity. Retold time and again the fictionalized account of an actual historical episode has been a staple of bunraku and kabuki theatre and, of course, Japanese movies from the silent era to adaptations from acclaimed auteurs like Kenji Mizoguchi (The 47 Ronin (1941)), Hiroshi Inagaki (Chushingura (1962) starring the great Toshirô Mifune) and Kon Ichikawa (47 Ronin (1994) pairing the great Ken Takakura with iconic J-pop teen sexpot Rie Miyazawa). This new version for 2013, marking the first Hollywood take on the time-honoured tale, assembled the cream of Japanese movie talent (Hiroyuki Sanada, Japan's most popular film star; Tadanobu Asano, their most feted chameleonic actor; Oscar nominee Rinko Kikuchi; and Kou Shibasaki, arguably Japan's biggest multimedia sensation – not merely a star but a galaxy unto herself) for added authenticity only to divert considerably from the source material with the addition of Keanu Reeves as a white, or at least mixed-race, male lead and big fantastical set-pieces with rampaging CGI monsters.

Of course Hollywood has a long, disreputable tradition of monkeying around with the cultural heritage of other nations for the sake of palatable mainstream (read: Anglo-American) entertainment but in this instance accusations of desecrating a classic were slightly misplaced. After all, down the years the Japanese film industry had been known to put a fantastical and in some instances science fiction spin on time-honoured literary works and folk tales, e.g. Legend of the Eight Samurai (1984) or Princess from the Moon (1987). Even Seven Samurai (1954) was refashioned into a steampunk sci-fi anime. Respected auteurs Kon Ichikawa and Kinji Fukasaku devoted themselves to making a string of films that put a post-Star Wars fantastical spin on traditional fare. In fact Fukasaku got there first having reworked the 47 Ronin into Crest of Betrayal (1994), a fast-paced, effects laden adventure full of monsters, witches and supernatural beings that was well-received in Japan as an event movie. Unfortunately no amount of whitewashing or effects trickery proved able to entice the mainstream audience. Worse films came out in 2013 but it was 47 Ronin that proved not just the costliest flop of the year but, according to some sources, of all time.

For those of us that love Japanese fantasy this is dispiriting news albeit predictable. Whilst the film has some positive qualities the mythological entities are clumsily shoehorned into what was once a straight samurai story. Worse yet, first-time director Carl Rinsch - never trust a director whose Wikepedia page describes him as a businessman first and filmmaker second – presents these giant kaiju in thuddingly prosaic fashion, bereft of the sense of wonder of recent similarly CG laden Asian epics like The Monkey King (2014). The one exception being the sequence in the Tengu cave wherein Oishi envisions his men slain by flying bird-goblins that briefly conveys a sense of surreal suspense. More problematic is the inclusion of half-breed Kai. Sure, one expects a big budget Hollywood treatment to include an American star but did the filmmakers have to be so blatant about it? The new narrative repeatedly stresses the samurai's prejudice against him which might be historically accurate for many Japanese at the time but undermines their heroism in defiance of the core message of the original story. We are shown Kai is nobler than any of the ronin as he lectures them on honour and in one scene – gasp! - actually bests iconic chanbara star Hiroyuki Sanada in a sword fight. Yeah, right...

Screenwriters Chris Morgan, who penned the last three Fast & Furious movies and Hossein Amini, Oscar nominated screenwriter turned director of The Two Faces of January (2014), refashion the story as an allegory for the death of old Japan with its rigid feudal traditions and prejudices, embodied by the ronin themselves and vengeful witch Mizuki, and birth of the new symbolized by Kai who lives by his passions and keen sense of right and wrong. By and large Rinsch fails to dwell on these nuances long enough to let the emotions seep through, for instance reducing an important portion of Kai's backstory to a throwaway monologue. Yet those segments devoted to Hiroyuki Sanada's Count of Monte Cristo-like fate are genuinely tragic and compelling with echoes of the actor's widely praised turn in The Twilight Samurai (2002). Each of the Japanese stars deftly handle their English dialogue (Sanada toured with the Royal Shakespeare Company) and exhibit their familiar charisma but are wasted in flat, clichéd. Fans of achingly lovely Kou Shibasaki will be especially mystified seeing her cast as submissive love interest when her stock in trade are fiery, feisty heroines. Check out Dororo (2007) or Battle Royale (2000) to see what she is capable of. Rinko Kikuchi fares better, sporting fantastic hair and sexier than ever, but then Hollywood traditionally has less qualms about Japanese actors portraying strong, proactive villains. Fans will likely savour the scene wherein Kikuchi briefly straddles Shibasaki.

To the film's credit it aims for a sober treatment rather than line the plot with corny jokes. It also refrains from having Keanu step in as J-megastars Sanada and Asano face-off and respects the original ending which retains its power to move. Veteran editor and occasional director Stuart Baird also ensures the action speeds along. Yet ultimately this is still the latest in a depressingly long line of Asian-American fantasies to fail at the box office. Some suggest mainstream viewers simply have no interest in Asian fantasy, but one would contend the problem lies with the treatment not the subject matter.